Rethinking procurement biopsy in donors with normal renal function: A barrier to kidney utilization without survival benefit

Abstract

BACKGROUND

Procurement biopsy remains widely used in deceased donor kidney transplantation, yet its value is uncertain in kidneys with preserved renal function. Concerns persist regarding sampling error, interpretive variability, and the potential for biopsy findings to contribute directly to organ discard. Whether procurement biopsy improves decision-making or graft outcomes in donors with normal renal function is not known.

AIM

To investigate whether biopsy adds clinical value or causes delay, misclassification without improving outcomes in donors with preserved renal function.

METHODS

Using national Organ Procurement and Transplantation Network data (2014-2024), we evaluated deceased donor kidneys with terminal epidermal growth factor receptor ≥ 60. Donor, recipient, and transplant variables were linked at the center level to reflect clinical decision pathways. Propensity-score matching (1:1 nearest neighbor, caliper 0.2 SD) generated balanced biopsy and non-biopsy cohorts. Center-clustered Cox models estimated the association between biopsy and death-censored graft failure. Mediation through cold ischemia time and delayed graft function was examined using sequential attenuation, with robustness assessed via E-values, restricted mean survival time, and decision curve analysis.

RESULTS

Of 158365 recovered kidneys, 46.6% underwent biopsy and were over six times more likely to be discarded (28.2% vs 4.4%), including 5.9% discarded solely due to biopsy findings, more than half with only mild abnormalities. The matched cohort comprised 52094 transplants with excellent covariate balance. Center-clustered Cox models showed biopsy was associated with higher graft-failure risk (hazard ratio = 1.12, 95% confidence interval: 1.05-1.19). Biopsy prolonged cold ischemia time by 42 minutes, mediating approximately half of its adverse survival association. Restricted mean survival time demonstrated a small but significant absolute reduction in five-year survival (-0.03 years). Decision curve analysis showed no meaningful improvement in clinical benefit from biopsy beyond standard clinical variables.

CONCLUSION

In deceased donors with normal renal function, procurement biopsy adds no prognostic value, increases discard and ischemic delay, and may hinder optimal utilization of otherwise transplantable kidneys.

Keywords: Kidney transplant; Procurement biopsy; Death-censored graft survival; Donor kidney discard; Renal function

Core Tip: Using national Organ Procurement and Transplantation Network data, we show that procurement biopsy in deceased donors with preserved renal function does not improve prognostic accuracy or graft survival. Instead, biopsy is associated with substantially higher discard rates and prolonged cold ischemia, with much of its adverse impact mediated through ischemic delay and early graft dysfunction. Advanced analytic approaches, including mediation, restricted mean survival time, and decision-curve analyses, demonstrate no added clinical benefit beyond standard donor and recipient characteristics. These findings challenge routine procurement biopsy in this donor population and support re-evaluating biopsy-driven acceptance practices to improve kidney utilization.